1. Field of the Invention
The present invention relates to radio communication technologies. More particularly, the present invention relates to a method for selecting a Policy and Charging Enforcement Function (PCEF) and a Policy and Charging Rule Function (PCRF).
2. Description of the Related Art
FIG. 1 is a schematic diagram illustrating system architecture of an existing System Architecture Evolution (SAE) according to the related art.
Referring to FIG. 1, a User Equipment (UE) 101 is a terminal device for receiving data. The Evolved-Universal Terrestrial Radio Access Network (E-UTRAN) 102 is a radio access network, and includes an eNodeB/NodeB, which provides an interface for accessing the radio network for the UE. A Mobility Management Entity (MME) 103 is responsible for managing mobility contexts, session contexts and security information of the UE. A Serving Gateway (SGW) 104 is mainly responsible for providing a function of a user plane. The MME 103 and SGW 104 may locate at a same physical entity. A Packet Data Network Gateway (PGW) is responsible for executing functions, such as charging and legal monitoring. The PGW 105 and the SGW 104 may be located at the same physical entity. A Policy and Charging Rule Function (PCRF) 106 provides Quality of Service (QoS) policies and charging rules. A Serving General Packet Radio Service (GPRS) Support Node (SGSN) 108 is a network node device for providing routes for the transmission of the data in a Universal Mobile Telecommunication System (UMTS). A Home Subscriber Server (HSS) 107 is a home sub-system of the UE, and is responsible for protecting user information, such as current location of the UE, an address of a server node, user security information and packet contexts of the UE.
FIG. 2 is a schematic diagram illustrating architecture of an existing Policy Control and Charging (PCC) according to the related art.
Referring to FIG. 2, when the existing monitoring and controlling function is executed, main participating nodes are the Policy and Charging Rules Function (PCRF), Policy and Charging Enforcement Function (PCEF), Traffic Detection Function (TDF) and Subscriber Profile Repository (SPR). The other nodes may include a Bearer Binding Reporting Function (BBERF), an Online Charging System (OCS), an OFfline Charging System (OFCS), and an Application Function (AF).
The SPR is configured to save subscription data of the user. In some networks, a User Data Repository (UDR) may be used in place of the SPR node.
A PCRF is a monitoring and controlling node. The PCRF determines monitoring policies, configures the upper limit of usage of application services, and sends the upper limit to the TDF or PCEF, to enable the TDF or the PCEF to execute the monitoring function.
The TDF or PCEF executes the usage monitoring function according to an instruction of the PCRF, and sends a report message to the PCRF according to the request of the PCRF or when the number of the users exceeds the upper limit. When the usage of the current service reaches the upper limit, the TDF or the PCEF sends a report to the PCRF.
The PCRF may determine whether to modify the upper limit to keep on monitoring the current service or to stop monitoring the service. The PCRF may send a request message to the TDF or the PCEF at any time, to ask for the usage of the current service. The PCRF has a derivation function. The PCRF may figure out whether the amount of the service used by the current user exceeds the upper limit of the usage of the service according to the report of different services. The PCRF determines whether to stop the monitoring function according to the report of the amount of the services used. Accordingly, whether the PCRF stops monitoring or modifies the upper limit of the monitored service is related to the updating of the subscription information and the updating of the policies of the operators. The current monitoring ability may apply to a service stream of a single data, the service stream of a group data, or a PDN connection. The monitoring function may be performed according to a static PCC criterion or according to a dynamic criterion.
In the 3GPP R-12, the operator introduces a series of new demands. The new demands include:
First: A group of users may be monitored. Users of the same group may share a fixed service consumption amount, while no other requirements are put forward for the users in the group.
Second: One monitored group may include several types of services. Especially, multiple services may belong to different PDN connections.
Third: The same services may belong to different monitored groups.
Fourth: One monitored group may include multiple services. The operator may exclude a service from the monitored group at any time.
At present, there is no corresponding scheme for satisfying the above demands.
Therefore, a need exists for a system and method for selecting a PCEF and a PCRF, to implement monitoring of group users and group services.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present invention.